<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .radio:checked {
            /* background-color: #3197EE;
            box-shadow: inset 0 0 0 4px #f4f4f4; */
        }

        .radio {
            outline: none;
            border-color: #3197EE;
        }
    </style>
</head>

<body>
    男<input type="radio" class="radio" name="sex">
    女<input type="radio" class="radio" name="sex">
</body>

</html>